LONDON (Reuters) - Raspberry Pi, the British computer company that floated in June, reported on Tuesday stronger-than-expected adjusted earnings of $20.9 million for the first half, sending its shares up 7% in early trade.

The group, which produces low-cost single-board computers and microcontrollers, said it sold marginally fewer devices than it expected, but sales were skewed towards higher margin products, boosting profitability.

Its flagship Raspberry Pi5,which retails for 46.60 pounds ($62.24) for the 2GB model, sold 1.1 million units in the six months to the end of June, it said.

It said it expected volumes to increase in the second half, supported by product launches, but the mix would result in margins returning to lower levels and it kept its expectations for the year unchanged.

Chief Executive Eben Upton said the IPO, two weeks before the period ended, was a "watershed moment".

"We saw strong uptake of our latest flagship SBC, Raspberry Pi5, the launch of the Raspberry Pi AI Kit, and the successful ramp to production of RP2350, our second-generation microcontroller platform," he said.

Shares in Raspberry Pi were trading at 364 pence in early trade, 30% higher than the 280 pence listing price.

($1 = 0.7487 pounds)

(Reporting by Paul Sandle; editing by Sarah Young and Susan Fenton)