Employees work on a turbine at the General Electric plant in Belfort.

General Electric's power business is still struggling, but the company is sugar coating this in communications with investors, according to a top analyst at J.P. Morgan.

"We believe a full accounting of the situation with a closer look at the data, even a rudimentary review, supports our view that GE is indeed losing market share in a stable" heavy-duty gas turbine market, J.P. Morgan analyst Stephen Tusa said in a note to investors.

"We see nothing here to change our negative view on Power, more so evidence of a company that appears to manage to headlines rather than on-the-ground fundamentals," Tusa added.

The analyst gained a wide following on Wall Street for his early warnings on GE's stock decline, beginning nearly three years ago. Tusa's notes, especially when J.P. Morgan adjusts its GE estimates, often move the company's stock.

His analysis of GE's power business focused on the company reporting 4.5 gigawatts in orders for heavy gas turbines in the first quarter. Tusa said this is well above what competitors reported.

Tusa said management explained the discrepancy by saying "there were several 'partner orders' that

don't go reported in units that bridge the gap."

"GE's 4.5 GW order number has generated a buzz across a Street consensus hungry for positive data points," Tusa said. "We believe that the headlines do not tell the whole story."

Here is how Tusa broke down the total reported units sold versus the "actual externally ordered" turbines last quarter.

"Beyond this cut of the data, however, the dynamics here raise concern around communications from a company that continues to get material benefit of the doubt around credibility, though appears to us to be stopping short of telling the whole story," Tusa said.

J.P. Morgan's analysis comes even after CEO Larry Culp told investors in March that GE's power business "is in a serious turnaround mode." Culp also told CNBC that GE has "a number of problems we need to work through this year," adding that "this is the year that we share with the world what those issues are."

The company did not return a call for comment.

GE shares slipped 0.87% Wednesday morning from Tuesday's close of $10.32 a share. J.P. Morgan has an underweight rating and a $5 price target on GE's stock.

Watch: GE will be transparent about its challenges in its turnaround plan, CEO Larry Culp says