(For a Reuters live blog on U.S., UK and European stock markets, click or type LIVE/ in a news window.)

*

Nov CPI due on Tue, Fed policy on Wed

*

Microsoft up on plans to buy LSE stake

*

Indexes up: Dow 0.91%, S&P 0.62%, Nasdaq 0.40%

Dec 12 (Reuters) - U.S. stock indexes rose at the start of an action-packed week on Monday, buoyed by Microsoft, while investors waited for inflation data and the Federal Reserve's policy decision later in the week amid rising worries of a recession.

Microsoft Corp rose 2% following the tech giant's deal to buy a 4% stake in the London Stock Exchange Group , powering much of Wall Street's gains.

The benchmark S&P 500 looked to rebound from its worst weekly performance since late September, sparked by dour comments from top U.S. executives and mixed economic data.

All eyes will be on inflation data Tuesday, expected to show that consumer prices increased 7.3% in November on an annual basis, though easing from the 7.7% rise in the previous month.

"The CPI report will show a continued decline in year-on-year growth," said Sam Stovall, chief investment strategist at CFRA Research, New York.

"Even though most people are expecting a 50-basis-point hike on Wednesday, they are still a little bit nervous that maybe Fed Chair Powell will surprise us with a gloomier-than-expected outlook."

Market participants are betting that the U.S. central bank will shift from its aggressive rate-hike path as the economy shows signs of a strain from its recent policy actions.

The Fed's two-day meeting is scheduled to end on Wednesday, with money market participants seeing a 91% chance of a 50-basis-point rate hike to 4.25-4.50%, and a terminal rate of 4.99% by May 2023.

Treasury Secretary Janet Yellen on Sunday forecast a substantial reduction in U.S. price pressure in 2023, while also acknowledging a risk of a recession.

Fears of an economic downturn have hammered Wall Street's main indexes this year, with the Nasdaq and the S&P 500 down 29.4% and 17%, respectively. The indexes are on track for their worst yearly performance since 2008.

At 12:04 p.m. ET, the Dow Jones Industrial Average was up 305.78 points, or 0.91%, at 33,782.24, the S&P 500 was up 24.45 points, or 0.62%, at 3,958.83, and the Nasdaq Composite was up 43.83 points, or 0.40%, at 11,048.44.

Eight out of the 11 major S&P sector indexes were in the green, led by energy, utilities and technology stocks.

Rivian Automotive Inc lost 3.6% after the company paused its partnership discussions with Mercedes-Benz Vans on electric van production in Europe.

Biotech firm Horizon Therapeutics Plc surged 15.2% following a buyout offer from Amgen Inc, while Coupa Software Inc soared 26.8% after agreeing to sell itself to private equity firm Thoma Bravo LLC.

Weber Inc climbed 23.5% after the outdoor cooking firm agreed to be taken private by controlling shareholder BDT Capital Partners LLC.

Advancing issues outnumbered decliners by a 1.40-to-1 ratio on the NYSE and 1.35-to-1 ratio on the Nasdaq.

The S&P index recorded two new 52-week highs and two new lows, while the Nasdaq recorded 42 new highs and 199 new lows. (Reporting by Shubham Batra, Ankika Biswas and Johann M Cherian in Bengaluru; Editing by Vinay Dwivedi, Anil D'Silva and Sriraj Kalluvila)