* Market disappointed with Xi-Trump summit deals so far

* Trade truce extension undecided, US official says

* China aviation stocks fall after Boeing ( BA ) deal

(Updates index move, chip stocks move and adds comments)

By Summer Zhen

HONG KONG, May 15 (Reuters) - China stocks wavered in

morning trade on Friday, with investors cautious heading into

the last day of a high-stakes summit between U.S. President

Donald Trump and China's Xi Jinping, which has delivered a few

deals so far.

China's blue-chip CSI300 Index and the Shanghai

Composite Index rose slightly after dipping more than

0.5% respectively in morning trade, easing further away from

their recent peaks. Hong Kong's benchmark Hang Seng fell

more than 1%.

The two leaders are scheduled to have tea and lunch on

Friday before Trump flies back to the United States.

Traders are closely watching for any positive signals from

the meeting, including a potential easing of tariffs.

Trump told Fox News Channel that China has agreed to buy 200

Boeing ( BA ) jets, a number that was far fewer than analysts

had expected.

Aviation stocks led the decline in morning

trade, down more than 2%.

Chip stocks, meanwhile surged 8% after China's

SMIC says foreign clients shifting orders back to China.

It was undecided whether the trade truce will be extended

after it expires later this year, U.S. Trade Representative

Jamieson Greer told Bloomberg TV on Friday, but added that deals

had been firmed up on Chinese purchases of farm goods, beef and

Boeing ( BA ) aircraft.

Xi told ​Trump on Thursday that negotiations on trade issues

had reached "balanced and positive outcomes", without

elaborating.

"I think we were optimistically looking at the meeting and

maybe half expecting some huge trade agreement to be proposed or

announced and from that view, it has disappointed," said Nick

Twidale, chief market analyst at ATFX Global.

During a state banquet on Thursday, Trump ​invited President

Xi to ​the White House ​for ​a visit on ‌September ⁠24.

"This was not a meeting aimed at a full reset of US-China

relations," said Cliff Zhao, chief economist at CCB

International.

It was more about resuming and promoting high-level

communication, reducing near-term uncertainty, and setting

clearer boundaries for competition, he added.

China's yuan maintained its strength as the

Trump-Xi meeting was underway. The currency hit a three-year

high against the dollar in the previous session.

The yuan retreated slightly after the People's Bank of China

set the midpoint rate at 6.8415 per dollar, 439 pips

weaker than a Reuters' estimate.

The yuan is up 0.5% against the dollar this month, and 2.9%

firmer this year.