DUBAI, July 28 (Reuters) - Dubai's biggest lender, Emirates NBD, posted on Thursday a jump of 42% in second-quarter net profit, boosted by higher income and lower impairments.

Emirates NBD's net profit of 3.5 billion dirhams ($952.98 million) for the three months to June 30 was up from 2.46 billion in the year-earlier period.

Net interest income rose 27% on the year in the quarter as higher interest rates fed through to margins while its Turkish subsidiary DenizBank also experienced strong loan growth and widening margins.

The bank said it was raising the group's guidance for net interest margins this year to between 3.2% and 3.3% from 2.7% to 2.8% previously, citing an improved loan and deposit mix with higher interest rates.

"We are extremely well-positioned for rising interest rates and will continue to invest in our international and digital capabilities to support further growth," it said in a statement.

Most Gulf central banks lifted their main interest rates by three quarters of a percentage point on Wednesday, moving with the U.S. Federal Reserve as their currencies are pegged to the dollar. ($1=3.6727 UAE dirham) (Reporting by Hadeel Al Sayegh; Editing by Clarence Fernandez)