UPDATE 1-Japan's Toshiba logs Q1 profit, keeps outlook

* Apr-Jun op profit Y29.5 bln vs consensus Y24.2 bln

* Keeps full-year forecast at Y250 bln, below consensus

* Shares close down 0.2 pct before results

TOKYO, July 29 (Reuters) - Japan's Toshiba Corp (6502.T) posted a fourth consecutive quarterly profit on Thursday on robust sales of memory chips and kept its full-year outlook for a doubling of operating profit.

Toshiba, its bigger rival Samsung Electronics Co (005930.KS) and other NAND-type flash memory makers are seeing surging demand for the chips as more and more consumers snap up devices like smartphones, digital cameras and portable music players.

The companies are also benefiting from tight supply and solid prices since a severe downturn in the sector over a year ago forced many NAND chipmakers to shrink production or go under.

Toshiba logged a 29.5 billion yen ($337.2 million) operating profit for April-June, beating three analysts' average profit estimate of 24.2 billion yen as per Thomson Reuters I/B/E/S.

It recorded a 37.6 billion yen quarterly operating loss a year ago.

Toshiba, also a major supplier of nuclear power plants, stuck to its operating profit forecast of 250 billion yen for the year to March, slightly below a consensus for 256 billion yen profit by 17 analysts.

Besides its chip and nuclear power businesses, it has been focusing on emerging areas such as smart grids and lithium-ion batteries for growth.

The NAND flash memory market is thriving right now, but some analysts fear that it is heading to another supply glut since makers have started to invest again. Toshiba recently started constructing its latest chip plant.

Research firm iSuppli said this month an oversupply of chips used for removable memory cards and USB drives triggered global revenue from NAND shipment to decline 6.5 percent in the April-June quarter, but it added the sector is expected to return to growth in the next five quarters.

Shares in Toshiba have fallen about 9 percent this year, underperforming a 3 percent slide in the electrical machinery subindex .IELEC.T during the same period.

They closed down 0.2 percent at 462 yen before the results, against a 0.1 percent fall in the subindex. ($1=87.47 Yen) (Reporting by Sachi Izumi; Editing by Muralikumar Anantharaman)