TOKYO, Sept 3 (Reuters) - Japanese shares jumped on Friday to their highest level in nearly six months, underpinned by hopes of an earnings recovery and potential economic stimulus later this year.

Nikkei share average gained 0.85% to 28,787.35, reaching its highest level since July 13.

The broader Topix, which have been outperforming the Nikkei for almost six months, hovered near its March 19 peak of 2,013 - its highest since 1991. At midday, it was up 0.8% at 1999.80.

"In terms of earnings revisions, Japan is now doing quite well in the world, which could be helping to bring fresh attention to the Japanese markets," Yuya Fukue, trader at Rheos Capital Works said.

Forward EPS of MSCI Japan has risen 30% so far this year, outpacing other major markets including U.S. , giving Japanese shares an edge after their underperformance earlier this year.

Steelmakers led the gains with a rise of almost 3%, with Nippon Steel up 3.7% and JFE Holdings gaining 4.5%.

Some chip-related shares retained their strength, with Lasertec adding 4.3% to solidify its big gains this week. Shin-estu Chemical rose 2.8%.

Hopes for a stronger government ahead of ruling party leadership race and a general election later this year are also propping up the market despite lack of clarity on how things will turn out.

There are questions over whether a growingly unpopular Prime Minister Yoshihide Suga can survive, but investors expect some sort of economic package ahead of the general election regardless of who will take the helm. (Reporting by Hideyuki Sano, Editing by Sherry Jacob-Phillips)